mtools: upgraded package to upstream

Upgraded sys-fs/mtools to version 4.0.18-r1 for all.
This includes a runtime locking fix.

BUG=chromium:508713
TEST=precq is happy

Change-Id: I674c3427cd9bdf2f3d7454b4c6122572d0f122e6
Reviewed-on: https://chromium-review.googlesource.com/410820
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
2 files changed